Magnetic connector



Sept. 8, 1959 \\\\\\\\\\\\llllll A. P. BUQUOR 2,903,667

MAGNETIC CONNECTOR Filed March 12, 1957 INV ENTOR.

Magni 12 mgm A TTKNE YS -wef 4United States Patent O MAGNETIC CONNECTORAdolph `Paschal Buquor, Washington, D C.

Application March 12', 1957., Serial No. 645,548

3 Claims. (Cl'. 339-12) This invention relates .toamagnetic electricalconnectors `and constitutes an improvement on the magnetic con- .nectordescribed inthe copending application of Adolph P. Buquor `and John, L.Buquor Serial No. 65,562, iiled December 16, 1948, for ElectricalConnector Having a `Magnetic Contact, now Patent No. 2,788,501.

The magnetic connector described' in said patent comprises a socketmember and a plug member adapted to be placed in the socket, bothmembers having side contacts arranged to slidingly engage each other tocomplete one side of a circuit therethrough. The plug member has an endcontact of paramagnetic material, ,preferably iron, andthe socket isprovided with al bottom contact comprising a permanent magnet arrangedyto attract and hold theend contact of the plug member to thus not onlycomplete a circuit through the connector but to also hold the Aplugmember in the socket without the necessity of em -ploying screwlthreads, spring fingers, bayonet-slot connectors or the like. It hasbeen found lthat permanent magnets of sufficient strength can be housedin the usual electrical socket to effectively maintain the plug andsocket members in Contact. The improvement of the present inventioncomprises the addition, to the structure of the copending application,of a resilient contact element positioned between the poles of themagnet in the base of the socket and made of a non-ferrous metal, suchas brass or Athe like. A suitable screw extends through the resilientcontact and serves to hold the magnet and resilient contact in assembledrelation to the socket and also comprises a non-ferrous circuit wherebyelectrical energy does not have. to pass through the pole faces of themagnet to complete a circuit. The arrangement is such that the plugmember is provided with a central portion adapted to extend between themagnet pole faces, which may be of solder or the like, and comprises anon-ferrous contact element on the plug member for engagement with theresilient contact of the ,socket to thus permit completion of a circuitthrough the connector without the necessity of passing of the electricalcurrent through the magnet poles or the paramagnetic. material 'of theend contactl on the plug member.

It is therefore an object of this invention toI provide an improvedmagnetic socket ofj simple construction, economical to manufacture, andreliable and efficient in operation.

Another fob'ject of the invention is to provide a magnetic4 electricalconnector wherein ferrous metals are not employedv to complete anelectrical circuit therethrough.

Further and additional objects and advantages will become apparent tothose skilled in theY art as the description proceeds in connection withthe accompanying drawings, wherein:

Fig; 1 is a sectional view. through an electrical connector embodyingthe improvement of this invention;

Fig. 2 is an end view of thev magnet of Fig. 1 with certain parts shownin section, as. viewed along the plane 2"-2 of Fig. 1;

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Fig. 3 is a perspective view of the magnet assembly of Figs. 1 and 2;

Fig. 4 is a vertical sectional view, similar to Fig. 1, of a modifiedform of magnetic electrical connector enibodying the present invention;

Fig. 5 is an end view of the magnet of Fig. 4, as viewed from plane 5 5of Fig. 4; and

Fig. 6 is a perspective view of the magnet assembly of Figs. 4 and 5.

Referring first to Fig. 1, the electrical connector is shown here, byWay of illustration only, as an adapter socket having a shell 2 providedwith screw threads 4 and adapted to be threaded into a conventionalthreaded socket as in use at the present time. The shell 2 is providedwith an outer sheath 6 of insulating material around its open endportion, preferably a molded plastic, With one or more inwardlyextruding resilient fingers 8 in the upper cylindrical portion of theshell 2. A pair of insulating discs 10 and 12k are placed on oppositefaces of the bottom of the shell 2 and serve to support a magnetassembly, in a manner to be described.

The magnet assembly comprises a rectangular body 14 of ceramic magneticmaterial. Such magnets are well known and generally comprise a sinteredbody of magnetic iron oxide. In any event the body 14 is permanentlymagnetized and` is substantially a non-conductor of electricity. Thebody 14 is so magnetized that the opposed faces 16 and' 18 (see Fig. 2)constitute the opposite poles thereof. A pair of rectangular plates 20and 22, of paramagnetic material such as iron, steel, or the like, areabutted against the pole faces of the magnet body 14 and extend upwardlytherefrom a substantial distance, as shown. The plates 20 and 22 serveto conduct and concentrate magnetic ilux from the magnet 14 to the edgefaces 24 and 26 of the plates 20 and 22, respectively. The edge faces 24and 26 thus constitute spaced pole faces of the magnet assembly. A clip27 of sheet brass or other non-magnetic material formed to any suitableconfiguration is employed to hold the plates 20 and 22 in assembledrelation to the magnet body 14 but preferably hold the parts somewhatloosely together so that the plates 20 and 22 may move slightly withrespect to the body 14 to permit accommodation of the faces 24 and 26 tothe end face of a plug member, as will be described. As shown, the clipmember 27 comprises a generally U-shaped body portion extending underthe magnet assembly and part way up the sides thereof and is providedwith inturned ears 28 turned into notches 30 in the ends of the plates20 and 22 and into an end notch 32 in the end of the magnet body 14. Bythis construction the magnet assembly is held in assembled relationshipquite loosely but positively.

The magnet assembly thus described is held in the shell 2 by means of ascrew 34 extending through the insulating discs 10 and 12 and through anenlarged opening 36 in the bottom of the shell 2. The screw 34 isthreaded into the bottom portion of the clip 27 and thus holds themagnet assembly in fixed relation in the shell 2 and electricallyinsulated therefrom.

A generally U-shaped resilient contact member 38 is positioned with oneleg thereof underlying the bottom of the magnet assembly and heldclamped between the magnet assembly and the insulating discs 10 and 12,the screw 34 passing through an opening in that one leg. The other leg40 of the resilient contact extends along the slot or groove definingthe space between the pole faces 24 and 26. The free end of the leg 40is preferably provided with a spherical crown 41 substantially at thecenter of the magnet assembly and is so biased by the normal resiliencyof the leg 40 that it normally' occupies the position shownin` dottedline in Fig. 1. The screw 34 and the resilient contact 38 are preferablyof brass or the like having low electrical resistance and it will beobvious that upon screwing the adapter of Fig. 1 into a conventionalthreaded socket, the screw 34 makes contact with the bottom contact ofthe threaded socket and the shell 2 becomes electrically connected tothe threaded shell of the standard socket.

A plug member, indicatedgenerally at 42, is shown -in this instance ascomprising the base of an electric light bulb and may be provided with athreaded metal shell portion 44 constituting a side contact thereon. Theshell portion 44 need not be threaded for the purpose of the presentinvention but is illustrated in such form since such a plug member couldthen be selectively used in either the magnetic socket of the presentinvention or a standard threaded socket, interchangeably.

As is usual in electric light bulbs, a body of insulating material 46 iscarried by the shell portion 44 and supportsan end contact 48,electrically insulated from the shell portion 44.

The end contact member 48 is a paramagnetic material, that is, amaterial that will be attracted to and held by a permanent magnet. Themember 48 further must be of sufficient mass that it will accommodate asufficiently large amount of magnetic flux, before saturation, todevelop the required holding force between the magnet and the plug.Numeral 50 indicates a central portion of the end contact 48 on the plugmember and may be a droplet of solder or the like, customarily employedto electrically connect a filament (not shown) of the electric lamp bulbto the end contact 48.

As shown in Fig. l, the mere sliding of the plug member 4Z into thesocket shown effects electrical connection between the shell 44 and thespring fingers 8. The paramagnetic member 48 spans the pole faces 24 and26 thereby completing a magnetic circuit and creating a very substantialholding force holding the plug member 42 in the socket. At the same timethe central portion 50 of the end contact on the plug engages the end 41of the leg 40` of the resilient contact member 38 to complete anelectrical connection from, for example, the filament of the lamp bulbto the screw 34 without employing ferrous metal as a necessary part ofthe circuit.

The resilience of the leg 40 is such that it normally occupies theposition shown in dotted line in Fig. l but may be readily displaced tothe full line position to exert firm contact against the portion 50without exerting sufficient upward thrust to materially diminish theholding force of the magnet. Obviously the plug member 42 may be veryeasily and readily either withdrawn from or placed in the socket and theelectrical circuits therethrough are completed without the necessity ofperforming any further manipulations. lt has been found that the partscan be held in such firm contact that a very substantial pull isnecessary to disconnect the plug from the socket.

In the event that the bottom face of member 48 is not a true planarsurface, or in the event that the magnet assembly is slightly cocked inthe socket, the plates and 2.?. may shift slightly with respect to eachother so that the pole faces 24 and 26 make snug surface contact withthe member 48.

While the socket member is shown in the drawings and described herein asan adapter to be screwed into a conventional threaded socket, suchillustration is by way of example only. It is to be understood that theinvention disclosed herein is not to be limited to an adapter but may beincorporated in a complete socket connected directly to wire conductorsor the like or permanently mounted in or on a wall or other support.Furthermore, the plug member 42 has been described as being an electriclight bulb but it is to be understood that the invention is ofsufficient breadth to include plug members connected directly toelectric wires or the like and need not be in the form of a light bulb.For example, the plug and socket connector of this invention could beemployed to connect an extension cord to the cord of an appliance or inmany other similar manners, all as will be obvious to those skilled inthe art.

Referring now to Fig. 4, which is a vertical section through a modifiedform of electrical connector, the socket again is illustrated, by way ofexample only, as an adapter for mounting in a conventional threadedsocket and comprises a threaded shell portion 60 secured in any suitablemanner to an upper ring 62 having upwardly extending spring fingers 64.A plastic or the like shell 66 of insulating material surrounds the ring62 and spring fingers 64 and defines the upper portion of the socket ofthe present invention. The shell 60 is provided with an enlarged centralopening 68 in its bottom wall. A permanent magnet 70 is secured in thesocket shell 60 by a screw or bolt 72 extending through insulating discs74 and 76 serving to electrically insulate the magnet 70 from the shell60. The magnet 70 is an integral onepiece metal permanent magnet, whichmay be of the type generally known as Alnico magnets and is providedwith a transverse groove 78 thereacross defining a space between polefaces 80 and 82. A resilient contact member 84, of generally U-shape, ispositioned in the groove 78 with one leg thereof resting on the bottomof the groove and through which the bolt 72 passes. A nut 86 is shown assecuring the resilient contact 84 to the magnet 70 and in turn securingthe magnet 70 to the shell 6ft in insulated relation thereto. The upperleg 40' of the resilient contact 84 is identical to the upper leg 40described in connection with Figs. l through 3. In like manner the plugmember 42' may be identical to the plug member 42 described inconnection with Figs. 1 to 3.

It will be obvious that in both modifications described herein the basicstructure and manner of use is the same in that a plug member having aparamagnetic end contact is provided with a central end contact portionof nonferrous metal adapted to electrically engage a resilient contactof non-ferrous metal in the socket and a permanent magnet in the socketengages the paramagnetic portion of the plug end contact to hold thesocket and plug in assembled relation and to complete an electricalcircuit through the connector.

By the employment of the resilient contact as shown and describedherein, applicant has taken advantage of the novel features of theelectrical connector claimed in the aforementioned patent but at thesame time has provided for completing an electrical circuit through theconnector without resorting to ferrous or the like metals as part of thecircuit. By employing the non-ferrous resilient contact describedherein, substantially no current flows between the magnet pole faces andthe paramagnetic member 48 and thus there is no tendency for the polefaces to become pook-marked or to erode as a result of the passage ofelectric current thereacross.

While a limited number of specific embodiments of the invention areshown and described herein, it is to be understood that they are merelyillustrative, that the invention is of a scope to encompass all formsand modifications falling within the terms of the appended claims.

I claim:

l. A socket member for a detachable electrical connector, comprising; asocket member having an opening therein, a first side contact on atleast one side of said opening, a permanent bipolar magnet in saidopening and having transversely spaced pole faces lying in substantiallya single plane extending transversely across said opening and definingthe bottom thereof, contact element mounted in said socket member,electrically insulated from said side contact, and having a resilientcontact portion in the space between said pole faces, said contactportion being normally outwardly of the plane defined by said pole facesbut easily resiliently deformable to move inwardly, between said polefaces, to a position inwardly of said plane, and low-resistancenon-ferrous means electrically connecting said resilient contact portionto a further c011- tact on the exterior of said socket independently ofsaid magnet.

2. A lsocket as dened in claim 1, wherein said magnet is a unitary metalmagnet having a groove across one face defining the space between saidpoles, said resilient contact comprising a generally U-shaped memberhaving one leg thereof lying along the bottom of said groove and theother leg thereof defining said contact portion, and fastening meansextending through said one leg and said magnet and serving toelectrically connect said resilient contact to a conductor externally ofsaid socket member and holding said resilient contact, magnet and socketmember in assembled relation.

3. A socket as dened in claim 1, wherein said magnet comprises a ceramicmagnet member having opposed polar faces, paramagnetic pole membersengaging said polar faces and extending outwardly therefrom, theextending portions of said pole members having edge surfaces deiiningsaid spaced pole faces, said resilient contact comprising a generallyU-shaped member having one leg thereof extending between the extendingportions of said pole member and defining said contact portion, theother leg of said U-shaped member extending under said magnet member,holding means holding said pole members to said .magnet member to forman assembled magnet, and fastening means holding said assembled magnet,resilient contact and socket member in assembled relation and serving toconnect said resilient contact toA a conductor externally of saidsocket.

References Cited in the le of this patent UNITED STATES PATENTS 961,600Freeman June 14, 1910 1,982,627 Baum Dec. 4, 1934 2,429,526 Savon Oct.21, 1947 2,738,476 Buquor Mar. 13, 1956 2,788,501 Buquor et al Apr. 9,1957 FOREIGN PATENTS 552,378 Great Britain Apr. 5, 1943

